Lighting stores and commercial buildings is a considerable expense to building owners. Typically, a lighting architecture is designed when the building is built and the lights are either turned on or off by the store manager during operating hours. Most lights are grouped into sections which are turned on or off as a whole. Some lights may have dimmers which allow a store manager to vary the intensity of groups of lights or individual lights.
Some store owners use timers to turn on and off lights, individually or collectively, especially in cases where the lamps need a warm-up delay before turning on completely and a cooling delay when turning off.
Most stores have large windows on at least one side of the building. Some also have atrium windows and light wells or window wells which allow natural light to penetrate the building and illuminate the merchandise.
The light intensity is evaluated subjectively by the store manager and is typically not adjusted even in days of great sunshine. Lights remain turned on near the windows as if there was no natural input.
There is a need to better control the input of artificial lighting in building where there is an input of natural lighting to save on energy costs.
Furthermore, relamping burnt lamps is very expensive and when a lamp is used constantly, it burns faster. There is also a need to increase the relamping period in commercial buildings.